Host: The Japan Society of Mechanical Engineers
Name : [in Japanese]
Date : November 19, 2024 - November 20, 2024
In this study, in order to understand the vortex shedding characteristics from an asymmetrical bluff cylinder, the flow features of vortex shedding from a square cylinder oscillating along the direction of the flow were observed by visualizing water flow experiment at the ranges of the frequency ratio f/fK=1~6, amplitude ratio 2a/d=0.67 and 1.00, and main flow velocity U=0.0654m/s. Experimental apparatus consists of the closed circuit water channel apparatus, an oscillating apparatus, a visualization apparatus, and a video recording apparatus. Use those equipment, the variations of mean vortex shedding frequency were investigated and the existence range of the lock-in was shown. As a result of the experiments, Even if it used the cylinder of asymmetrical cross-sectional shape for the flow axis, producing the lock-in phenomenon was observed. It was shown that the lock-in range is in the tendency which will narrow if oscillating half amplitude becomes large. It was found that distribution of the flow pattern of the lock-in region and changes process change with degrees of angle of attack.
